1. Field of the Invention
The present invention relates to a belt for a continuously variable transmission in which a pair of metal ring assemblies are supported in a pair of ring slots and include a plurality of metal elements. Particularly, the invention relates to a belt for a continuously variable transmission in which each ring slot in the metal element is defined by an element body, a neck, and an ear. The element body includes a pulley-abutment face abutting a V-face of a pulley and a saddle face supporting an inner peripheral surface of the metal ring assemblies while the ear includes a lower ear face opposite an outer peripheral surface of the metal ring assembly with a gap defined therebetween.
2. Description of the Related Art
A conventional belt for the continuously variable transmission is known from the disclosure of Japanese Patent Publication No. 2-19338, in which a metal element is formed so that the width of the lower ear face facing the ring slot is less than 75% relative to the width of the metal ring assembly, thereby reducing the weight of the metal element. The lower ear face of the metal element is inclined at 2° to 5° so that the ring slot has an outwardly increasing groove width, and the lower ear face is formed into a curved convex face opposite the outer peripheral surface of the metal ring assembly. The structural configuration of the conventional metal assembly provides optimal interference between the lower ear face and the metal ring assembly to prevent premature wear of the metal ring.
In the conventional belt, however, since the width of the lower ear face is less than 75% relative to the width of the metal ring assembly, a laterally outer end of the metal ring assembly protrudes to a great extent outwardly from the ring slot. Therefore, when the metal belt formed by assembling the metal elements to the metal ring assemblies is transported as an independent item or even when assembled to the continuously variable transmission, the laterally outer end of the metal ring assembly protruding from the metal element tends to interfere with other articles, leading to the outermost metal rings being significantly damaged. The outermost metal rings are exposed to severe conditions mostly among a plurality of the laminated metal rings, and the damage to the outermost metal rings greatly affects and diminishes the durability of the entire metal belt.
Also, the conventional belt suffers from the problem of the metal ring assembly falling from the slot during transportation or assembling of the belt because the laterally outer end of the metal ring assembly protrudes extensively outward from the ring slot. Therefore, a clamp or tie-lap is required to prevent the metal ring assembly from falling, which leads to an increase in the number of assembling steps and cost.